Reading Charts and Graphs You see them everywhere: pie charts, bar graphs, and line graphs represent important information. How do you read them and what do they mean?

Writing down information into a report is not always the best way to express information. People often use graphs because they are a simple, yet effective, way of showing statistical data. It is important for students to be familiar with a variety of graphs, since each one is best suited to represent certain types of information. This presentation will show you how to interpret and construct bar, column, pie and line graphs.

Bar and Column graphs These graphs are useful for comparing facts. Bar and column graphs help us to see relationships quickly.

Bar graphs: The bars provide a visual display for comparing quantities in different categories. Another name for a bar graph is a bar chart. Each part of the graph has a purpose. Title The title tells us what the graph is about labels The labels tell us what kinds of facts are listed bars The bars show the facts Grid lines Grid lines are used to create the scale categories Each bar shows a quantity for a particular category.

Questions What is the title of this bar graph? What is the range of values on the Horizontal axis? Which after school activity do students like most? How many students like to talk on the phone? How many students like to earn money? List the categories in the graph from greatest to least.

Column graphs: The columns provide a visual display for comparing quantities in different categories. Questions What is the title of this column graph? What is the range of values on the vertical axis? How many categories are in the graph? Which food had the highest percentage of sugar? What percentage of sugar is in soda? What is the difference in percentage of sugar found in ice cream and crackers?

Pie charts: Pie charts use different-sized sectors of a circle to represent data. When all the sectors are combined together it forms a complete disk. STUDENT LEISURE ACTIVITIES Questions What is the most popular leisure activity What percentage of students enjoy walking as a leisure activity? Which is the least popular leisure activity?

Line graphs: A graph that uses points connected by lines to show how something changes in value (as time goes by, or as something else happens). Let’s define the various parts of a line graph. title The title of the line graph tells us what the graph is about. labels The horizontal label across the bottom and the vertical label along the side tells us what kinds of facts are listed. Scale The horizontal axis across the bottom and the vertical axis along the side tell us how much or how many. points The points or dots on the graph show us the facts. lines The lines connecting the points give estimates of the values between the points.

Questions? How many points are in the graph? What is the range of values on the horizontal axis? What is the range of values on the vertical axis? What was the highest value recorded? What was the lowest value recorded? Did Sam’s weight increase or decrease over time?

Interpreting Data To interpret (or “read”) a graph, find the information you are looking for along either the “x” or “y” axis. Follow that line along until you find the point value that corresponds with a number value on the opposite axis. In pie graphs, the larger the slice, the larger that piece of information is represented in the data.

In groups of 4-5, you will need to analyse a variety of graphs related to different lifestyle diseases and answer the set questions provided. What trends do theses graphs reveal about each disease, are there differences between males and females, differences in months, who is most affected by the lifestyle disease?? These are some questions you’ll need to answer based on the graphs provided!!!